from sys import argv

script, input_file = argv

def print_all(f):
     print(f.read())
     
def rewid(f):
     f.seek(0)
     
def print_a_line(line_count, f):
     print(line_count, f.readline())
     
current_file = open(input_file)

print("First let's print the whole file:\n")

print_all(current_file)

print("Now let's rewind, kind of like a tape.")

rewid(current_file)

print("Let's print three lines:")

current_line = 1
print_a_line(current_line, current_file)
rewid(current_file)
current_line = current_line + 1
print_a_line(current_line, current_file)

current_line = current_line + 1
print_a_line(current_line, current_file)